Scientists have finally found where Waldo was hiding—well, the clam version, that is.

Researchers have discovered a new species of “alien” clam living on the Pacific coast of North America in sea urchin spines. The clam, Waldo arthuri, is in the genus Waldo, which was named for Waldo Schmitt, a famous researcher at the Smithsonian Institution. Finding it was the result of a 30-year manhunt (er, clam hunt?) by Paul Valentich-Scott, an invertebrate zoologist at the Santa Barbara Museum of Natural History.

The tiny Waldo clam. Photograph courtesy Diarmaid Ó Foighil

Although this new find doesn’t look anything like the character in the Where’s Waldo? books for children, who is famous for his red-and-white striped shirts, Valentich-Scott couldn’t help but think of the parallels between Waldo and his three-decade-long effort to search out this strange clam. (Also see “405-Year-Old Clam Called Longest-Lived Animal.”)

A colleague first spotted the newly named species during a mid-1980s mission to study California‘s coastal biodiversity. While examining some debris, the researcher noticed a tiny clam living on a heart urchin (Brisaster latifrons). Unable to identify it, the team called clam expert Valentich-Scott for help.

“I saw right away that it was something very, very unusual. Other than the general group where it belonged, I had no idea what it was,” Valentich-Scott said.

For one, it doesn’t look at all like the clams we’re used to seeing and eating for dinner—hence the alien comparison. The new clam’s shell is thin, fragile, and really tiny at only about five millimeters long—and the clam inside is even smaller. Unlike many types of clam, it can move on its own, lifting its shell over its body and scooting along the bottom of the ocean “a lot like a snail would,” he said. (Watch video: “Clams: Not Just for Chowder.”)

The clam lives in a close symbiotic relationship with the heart urchin, snuggling up, likely for protection, in the urchin’s spines.Scientists still aren’t sure what the urchin gets out of the pairing.

Bar Breakthrough

Although Valentich-Scott knew he had a really interesting clam on his hands, he didn’t know whether he was looking at a new species or a previously discovered oddity. So he kept his eyes peeled, and by 2002, he had enough data to place the odd clam in the genus Waldo. But he still didn’t have enough specimens or DNA sequence data to deem it a new species.

But then a breakthrough happened a few years ago—not on the ocean or in the lab, but in a bar. Valentich-Scott was relaxing at a conference and enjoying a few drinks with fellow scientist Diarmaid Ó Foighil, now a researcher at the University of Michigan, when Foighil began describing a strange clam he had discovered in the waters off British Columbia. When Valentich-Scott started sharing his own findings, he knew he had finally found Waldo.

Unlike Valentich-Scott, Foighil had managed to keep some of his specimens alive. From these, the scientists worked together to uncover details about W. arthuri‘s life cycle. Like most clams, W. arthuri is a hermaphrodite. But unlike most clams, it broods its young, protecting the fertilized eggs in its gills until they’re old enough to survive on their own. This information helped confirm that the team had, in fact, found a new species.

The parents usually deposit their young offspring on the same urchin where the parents are currently living. “You’ll see several generations of these clams all living on the same urchin,” said Valentich-Scott, whose study was published July 12 in the journal ZooKeys.

Now that we know about Waldo arthuri, here’s hoping there are still some Waldo clams out there yet to be found—even if they’re not wearing red and white stripes.

Post a comment

Blog Search

Search for:

We’re Moving!

As of October 22, 2014, Weird & Wild will be hosted on National Geographic's main news site. We'll continue to be your source for all things naturally bizarre—and as always, please send your feedback to newsdesk@ngs.org.

Weird & Wild Contributors

Posting Rules

Opinions expressed in blogs are those of the blogger and/or the blogger's organization, and not necessarily those of the National Geographic Society. Bloggers and commenters are required to observe National Geographic's community rules.